This investigation will evaluate the impact of severe malnutrition on factors in serum responsible for opsonization of bacteria and will assess the effect of dietary therapy alone or dietary therapy plus replacement of opsonins on morbidity and mortality in young children acutely malnourished. This proposal is a three stage sequential investigation with built in decision points for continuation of the study. Stage I will be the determination of the natural history of opsonic function in six children recovering from acute malnutrition. Stage II, will be a carefully controlled trial, under metabolic ward conditions, of intravenous fresh frozen plasma (FFP) or intramuscular gamma globulin on opsonin function and complement activity in acutely malnourished children. Six children will receive intravenous FFP and six children will receive gamma globulin. Two groups of six children will receive a purified protein fraction of human serum (plasmanate) as control groups; this product does not contain complement activity or immunoglobulin. Stage III will be a double blind clinical trial of parenteral plasma or gamma globulin therapy in accordance to the results of Stage II. This portion of the study will be undertaken only if warranted on the basis of results from Stages I and II.